道路景观保护中的变化与环境

作者：海蒂·霍曼

翻译：何明一 王亮

校对：王晞月

Text:　Heidi Hohmann

Translator: HE Ming-yi and WANG Liang

Proofreading: WANG Xi-yue

道路景观保护中的变化与环境

作者：海蒂·霍曼

翻译：何明一 王亮

校对：王晞月

Text:Heidi Hohmann

Translator: HE Ming-yi and WANG Liang

Proofreading: WANG Xi-yue

杰克逊、克雷和其他相关人士对文化景观的研究及文献中包含了大量道路景观的内容。然而，交通廊道的保护实际上面临着许多挑战，其中大部分来自于他们长且窄的这一特点：虽然道路的结构（路基、路肩、涵洞）相对单一，且管辖权往往属于同一机构，道路本身维护相对简单。然而，廊道环境的保护通常很难，不仅由于它耗资巨大，利益相关者庞杂，还因其快速的变化。道路景观是社会环境下庞大的通讯、交通网的一部分，加之迅猛的技术变革对其产生的影响，使得道路成为“快速变化”的景观，即其使用方式、使用感受和自身特征都随着时间的推移而不断变化。考虑到如此的变化，长距离交通廊道的保护应该如何完成或根据时间的推移进行调整？来自美国本土的4个研究案例阐释了在地方、区域和国家尺度上道路景观保护所面临的挑战。论述了公园道、风景道和高速路的保护方法，及在这种保护方法下资源的动态转化与演变。

道路；景观；文脉；公园大道；乡间小路

1　简介

20世纪末涌现出一系列关于“日常”文化景观的研究，如J.B. 杰克逊对于文化景观的思想意识流研究和格雷迪·克雷对路旁“带状空间”的研究。此后便鲜有关于机动车道路的文化景观研究[1-2]。这可能是部分由于我们不再乐观地看待公路和它所代表的机动车文化，而把它们看作造成全球气候变化的元凶。道路是“杂乱”的文化景观，它并非基于传统的、历史悠久的人地关系，而是一种通用的全球文化的代表，并常作为其他文化景观的负面因素而存在——它充当了技术的传输带，也充当了栖息地的分隔板。

道路的“杂乱”也体现在他们难以恰当地融入定义明确的文化景观体系中。联合国教科文组织为文化景观定义了3个类别，如表1[3]。道路似乎属于刻意创造的、“有明确定义的景观”的范畴。然而，它也有 “有机演变的景观”的特征，并且可以被视为“连续的景观”，这一定义根据社会和经济对于科学技术的要求而提出，以应对自然环境的相关问题。这些要求包括宏观的融资和建设，使道路成为永久景观的同时允许其发生动态变化。大量经济投资和大型的建设场地往往意味着道路更容易被适应，而不是被取代或被遗弃。快速变化的机动车科技、迅速增长的人口及其流动性，导致道路使用率的增加、司机群体的增加与变化。因此，道路可以被描述为“快速变化”的景观[4-5]。

Translator:

HE Ming-yi， who was born in 1991, is a Master student in School of Landscape Architecture, Beijing Forestry University.

WANG Liang, who was born in 1993, is a Master student

in School of Landscape Architecture, Beijing Forestry University

校对：

王晞月/1992年生/女/硕士/北京林业大学园林学院（100083北京）

Proofreading:

WANG Xi-yue, who was born in 1992, is a Master student in School of Landscape Architecture, Beijing Forestry University

另一个使道路变成“混乱”景观的原因是，它很难被定义：到底什么是它的资源？是道路、道路使用权、道路上的视野，还是道路所穿越的景观？在最近一次关于道路的文献调查中，Grazuleviciute-Vileniske和Matijosaitiene试图使用复合模型解决这个问题，可简化如下：

A：作为文化遗产的道路（“历史之路”）；B：作为文化遗产的道路景观（“具有特殊意义的语境”）；C：道路景观中的文化遗产（“紧邻道路的历史文物”）[6]。

Grazuleviciute-Vileniske和Matijosaitiene所提出的分类系统的意义在于它有助于确定什么样的道路特征和元素是有价值的，并因此值得保护。如果道路被视为文化遗产，那么道路上的工程结构（桥梁、涵洞、路缘石）是有价值的；如果道路周边的景观是文化遗产，那么从道路中望去的景观元素（灌木篱墙，田地，农用构筑物或其他从道路中望去所见的构筑物）是值得被保留的、有重要意义的元素；如果道路经过文化遗产元素，那么道路旁边的文化标志物（历史建筑、遗址、遗迹）就是值得被保护的目标。然而，这种模式有一定的局限性，实际上许多道路都同时表现出了3个类别的特点。Grazuleviciute-Vileniske和Matijosaitiene也承认了这一事实，将“混合道路”作为分类框架里的一小部分。

这些大多涉及道路及其周围环境之间的关系，它们使保护历史悠久的道路景观变得具有挑战性。在道路上的变化可能会影响环境，而环境的变化也可能会影响到道路。当从理论跨越到实践时，往往只有极少的情况下，一条道路能够恢复到它的历史状态，更多的往往是需要根据道路被修建、使用、或感知的方式进行保护和改造。在这篇文章中，列举了美国地方、区域以及国家尺度上的4个案例，以阐述变化与环境如何与道路景观的保护相关联。下面的案例研究首先将道路分为4类，然后描述了道路的保护工作是如何作用于道路及其保护实践方法的调整和转换的。

2　案例研究1.边缘岩石大道

1 环科罗拉多的岩石边缘大道 （海蒂霍曼提供）Rim Rock Drive in Colorado（ Credit: Heidi Hohmann）

表1　世界遗产名录之文化景观，定义于《世界遗产文化景观：保护和管理手册》Tab. 1 World Heritage Categories of Cultural Landscapes, as defined in the World Heritage Cultural Landscapes: A Handbook for Conservation and Management

岩石边缘大道（Rim Rock Drive），位于科罗拉州的弗鲁塔，22.42英里（36.08km）长，可被定义为历史性道路或是文化遗产道路。这是体验科罗拉多国家纪念区（图1）的主要路径。科罗拉多国家纪念区建立于1911年，是一个相对较小的（20 500亩/ 8 300hm2）的公园，用以保护前寒武纪、三叠纪、侏罗纪和白垩纪的重要地质特征。岩石边缘大道曾是一条原始的乡间小道，由公园支持者约翰·奥托建造，但在大萧条时期，国家公园管理局（NPS）利用民间护林保土队（CCC）的劳动人员，扩展并修建了道路，将其用作汽车公路。这条道路的修建展示“史诗”般的工程图景和及其陡峭的坡度；在其修建期间，大面积的岩石被炸开用以铺设路基、在悬崖峭壁上打通隧道；建造大型挡土墙，将道路架设在狭窄的平缓区域。这里虽然气候相对干燥，但经常会有短暂而激烈的降雨，所以修建了大大小小共200个涵洞，大约每英里（1.61km）10个，用以及时排走降水。1931-1950年间，这条道路被记录在美国历史名胜名录上，其重大的历史意义在于它独特的结构和工程，并能够将交通和娱乐整合在一起。

这条道路具有高度的完整性，并经历了相对较小的变化，大部分区域都处于正常状态，鲜有因时间原因导致的工程恶化和由于原始结构缺陷造成的问题。但问题出现在比正常尺寸小的涵洞和洼地上，它们无法充分处理暴雨带来的积水（这一问题自1939年就被发现）。传统的基于识别和评估道路特征的保护方式已在道路保护方面表现得相当出色。其中包括挡墙修复，道路重铺，涵洞维修和更换。经协商，美国联邦公路管理局在1990年出版的《公路设计的灵活性》一书中限制了护栏只有最陡的路段才能使用。因此，沿着这条路上许多被认为是不太安全的历史区域被保护了起来，目的是为了维护这条道路原始的驾驶体验。

这条道路上导致变化发生的主要压力来自于周边地区人口的增加。2014年，科罗拉多州在美国的人口增长率中排名第四，主要因素是人口迁入；自2000年以来，大章克申附近的人口增加了43%[7]。这导致了长途旅游业和当地娱乐业的增长：公园的到访量在过去的两年已达创纪录水平，这意味着大量的的游客游览过边缘岩石大道。

作为人口增加的结果，这条道路主要发生了两个变化，但这两个变化都不会影响历史悠久的道路本身的结构。首先，是整体环境的变化，视角和视域都已经发生了很大的变化，包括场地地理环境的背景中人类聚落和环境污染的出现等。这样的变化或许在晚上表现更为明显，当光污染从停车场、购物中心引人注目的高压钠灯中射向道路的整体环境，这场景更像人类纪元而非前寒武纪。其次，是潜在社会功能的增加。科罗拉多，特别是大章克申都因其拥有积极活跃的公民而闻名，现在这里还举行重要的个人或团体的骑行、长跑等活动，包括重要的年度马拉松。这条道路对于这些活动来说几乎是完美的长度，同时拥有有趣的（和具有挑战性的，2 000英尺（609.6m）高差）的路线。这样的用途似乎对道路的结构和保护有较少的影响，而对公园职工和维护方面的影响较大。作为一个公共景观，公园对于这些活动应该尽量缩减收费或者直接免费。

3　案例研究2.殖民地公路

殖民地公路长23英里（37.01km），可以被定义为历史道路和拥有文化遗产景观的公路。它位于弗吉尼亚州，于1933年由国家公园管理局设计建造，并作为殖民国家历史公园的一部分。以布朗克斯河大道和弗农山纪念公园作为范本，道路构建出了“现代”的、富有艺术性的特征。这条路并没有连接公园，而是连接了3个古迹景观：詹姆斯敦（1607年英国人在美国的第一个聚居地），威廉斯堡（弗吉尼亚殖民地国会大厦）和约克城（康华里投降地，标志着美国独立战争的结束）。在施工建设的时候，殖民地公路采用了创新的技术，即暴露的骨料表面和3车道的设计。3车道设计并没有道路标线，可以被认为是种“退化”的设计模式，因为技术的改进以及中央分隔带成为标准这样的设计即被放弃。同时期的其他先进或创新的功能也被采用，包括流线型道路的设计，以及能将道路建在潮汐河口之上的现代混凝土桥梁。这些现代的桥梁与独特的殖民地风格手工砖建造的桥梁形成鲜明的对比，沿着道路看过去这样的桥极具透视的美感。殖民地公路分前后两个阶段完成，从1933年到1941年和从1946年到1958年，中间被二战打断。值得注意的是，斯坦利·阿伯特曾在职业生涯初期为吉尔摩·克拉克设计过威彻斯特郡园道，并在上世纪30年代为国家公园管理局设计了蓝岭公园，在战后主持设计了殖民地公路的第二阶段。这条道路在历史上具有重要意义，不仅因为其独特的工程和景观，更因为它与交通和历史保护运动的之间的关联[8]。

现在，道路保护的主要问题之一是周边地区的人口增长。这条路曾经穿过林地，现在它穿过的是住宅开发项目（图2）。这种增长对道路景观有两个影响：首先是道路开始用作上下班的通勤，特别是在不断发展的城市威廉斯堡的周边区域。第二是由于发展的需要增加了防渗铺设，结果增加了雨水径流。道路的排水系统主要由直径18-24英寸（45-60cm）的砖材涵洞组成，这个系统最初设计时用来处理乡村径流。如今，它难以处理日益增加的水量，造成道路积水，河岸的侵蚀以及林地退化等问题。国家公园管理局运用了传统“翻修”的保护方法，对作为基础设施的涵洞进行更新改造来解决这个问题。其中包括替换年久的涵洞管道，升级新的排水结构，在一些区域使用比原始大小大两倍的涵洞管道，特别是在某些关键洪水易发位置[9]。这些涵洞管道虽然更大了，但混凝土管道仍被砖所覆盖包裹。他们的设计遵循美国保护指导准则，这一准则包含在在内政部长的历史地产处理标准中。这一标准中，历史地产应属于现存的资源，与新的构筑物区分开来（内政部长）[10]。值得注意的是，这种恢复道路排水设施的措施是一种温和的处理方式，因涵洞管道的变化方向平行于道路，并不在驾驶者的视域范围之内。

这个研究表明，随着时间的推移人们对道路的感知是如何被变化的，以及它的使用方式可以通过怎样的保护处理进行转变。在其建造的时候被视作科技进步的代表，虽然有一部分道路是在第二次世界大战后完成，只有不到50年的历史，殖民地公路依然能够被看作是一个历史性的道路。同样，一旦为游客和娱乐规定了特定的路线，道路的另一部分就会被看作是通勤的路线——这和岩石边缘大道新增的休闲娱乐功能不同。令人高兴的是，传统的保护技术促进了功能的转换，同时也减慢了特征的改变。

4　案例研究3.爱荷华林肯公路

2 穿越威廉斯堡的殖民地公路路线，展示了最近的房地产发展和集水区的水流方向.（谷歌地球（陆地卫星）的地图数据）Route of Colonial Parkway through Williamsburg, showing recent housing development and direction of water flow in watershed. （Map data from Google Earth (Landsat)）

3 用于分析历史完整性道路基本元素，以惠特兰西部的典型路段为例，1926年（提姆·凯勒和彼得·巴特勒提供）；下面的历史图片由密歇根大学专门收藏.Primary elements of the road used for analysis of historic integrity, based on typical section west of Wheatland, ca. 1926（Credits: Tim Keller and Peter Butler）; underlying historic image courtesy of University of Michigan Special Collections.

作为美国第一个横贯大陆的高速公路之一，林肯高速公路横跨美国3 400英里（5 470km），被认为是一条历史性的道路或者说是一条象征着美国文化遗产的道路。“林肯高速公路”这个概念是由一群以Carl G. Fisher为首的汽车实业家在1913年提出的。这些实业家们同时也创立了林肯公路协会（LHA）。公路不是由联邦政府资助的，而是由林肯公路协会（LHA）的地方分会和地方（州、县）政府资助。他们时常会利用现有的道路和其他人建立的新路线去建设高速公路。这个建造过程通常包括“英里试建”策略，道路的建设者们运用最新的道路建设方法建立近1英里的段落，然后，地方政府可以从中选择施工道路的标准，这些标准包括混凝土铺装、护栏和种植。其中最著名的案例位于伊利诺斯，是由著名建筑师Jens Jensen设计的。林肯公路是具有重大意义的，因为它培育了汽车文化，促进了道路建设的制度化和规范化，并最终促进了1956年联邦公路法案和美国州际公路系统的形成。

在爱荷华州，建造了约长达300英里（480km）的林肯高速公路，其中一些路段沿着现有的砾石路线，一些沿着新路线。林肯公路协会爱荷华分部试图确定一个“最佳路线”，所以路线前后被更改了许多次。最终，道路被重编为美国第30号高速公路。尽管爱荷华林肯高速公路成为了一个著名的国家线路，却在1960年后被州际80号公路夺取了光彩，因为洲际80号公路复制了林肯公路南部40英里（64.37km）的线路。林肯公路随后成为一个区域路线，主要是为本地人服务。今天，它仍具有重大历史意义，因为它对于1913年至1956年美国交通运输和汽车文化的发展有着显著作用。

今天，各个州对于林肯高速公路的保护都各有策略。在爱荷华州，州和县级政府对于道路的保护非常积极，因为爱荷华州有林肯公路协会的分部，这个分部在1992年重新建立，以“保存和恢复有关高速公路的记忆来歌颂它的意义和对国家的重要性”。在2004年，爱荷华交通部（IDOT）聘请爱荷华州立大学测绘、分析并策划了一个历史道路廊道的管理计划，旨在解决3个主要问题：道路的历史设计及特点，路旁建筑，可以追溯到1913-28年的周边区域的发展。通过比较现有的条件和历史照片，他们将交通部负责的工程层面和内政部相关的历史层面进行关联整合[11]。这使得主要元素更具有识别性，这是保持道路景观完整性与特征的关键，而次要元素的丢失可能对其完整性的保持并无影响。主要元素包括：线性关系，与铁路的联系，路旁种植，路面材料，道路通行权的范围，路沟和路肩的材料，相关的设施，以及具有高度完整性和悠久历史的土地使用状况（例如，农业使用）（图3）。次级元素包括路面宽度、结构、附属零件、边坡与边沟，和周边历史上土地利用完整性较低的风景。测绘和规划需要大量利益相关者的投入，包括与县级工程师、爱荷华林肯公路协会、30号公路联盟（一个推动4车道的高速公路发展的地方经济发展集团）及爱荷华市民中焦点群体（包括农民，上班族，进行休闲娱乐活动的使用者）进行协商。

凯勒和巴特勒的走廊管理计划使得林肯公路成为了一个遗产景观道。在美国，景观道是联邦公路协会（FHWA）国家项目的一部分，该协会在上世纪90年代为公路的防护提供资金。在2012后，这个项目被转移至各州，并且自从2006年以后，林肯公路的爱荷华州段就已经被爱荷华交通运输部、当地县工程师和一个非盈利组织共同管理。

在景观道的模式下，林肯公路的保护已很大程度上聚焦于因文化遗产旅游而得到发展的社区和经济。虽然关键的工程特征（如桥梁和砾石路段）被保留了下来，但是道路已被改造成了一个营销工具，用以支持当地的企业和吸引旅游业绕过南部的州际公路。其他国家的研究显示，道路名称的选定能够增加旅游量和旅游收入，虽然确切的经济效益很难量化[12]。在许多方面，今天的林肯高速公路不仅是一个地方，也是一个概念和品牌。尽管历史性的元素正在丢失，道路的意向却以林肯高速公路为载体而保持活力。在其他地方，一些社会事件使得林肯公路的记忆变得鲜活，例如长达300英里（482.80km）的义卖和一年一度的老爷车巡展。这种概念又经众多被批准的独立网站的宣传而进一步被强化。这些网站通过使用智能手机即可观看，免去了实际解说的需要并吸引了新的观众。尽管将林肯道路重塑为“景观道”并没有带来道路本身保存价值的提升，但是它已经显着改变了道路的价值和体现方式，并通过道路穿行的社区表现出来。

5　案例研究4.爱荷华州州际80号公路

4 20世纪50年代完成后的80号州际公路，公路地图（左）和近期实景（右）.（海蒂·霍曼提供）Interstate 80 in 1950s, after completion, from highway map　(left) and today (right). Credit: Heidi Hohmann

州际80号公路（I-80）取代林肯公路作为爱荷华州最重要的东西跨大陆运输道路。这条道路绵延306英里（492km），是1956年联邦援助公路行动（也被称为国家州际公路和国防公路行动）的一部分，这个项目提供250亿美元用于建设美国41 000英里（65 983.10km）的公路。州际80号公路的设计参照19世纪50年代的FHWA标准，是一个菱形和四叶式固定的4车道立体交叉道，其路线高效，具有长螺旋的曲线形态和路旁的服务设施。这条道路用时14年建造完成，它的第一段是在1985年建造完毕，最后一段在1966年竣工。在20世纪80年代早期，交通量就已经达到了设计的预期，所以在1985年到1988年间，对道路全长进行了重新建设（图4）。

洲际80号公路是一条重要的越野路线，承载着大量的卡车和汽车的通行。在爱荷华州，它穿过了美国的一个主要农业区——“美国玉蜀黍种植地带”，这是一个由玉米和大豆组成的广阔的景观，其上点缀着历史上和现代农业使用的农用构筑物。这种景观虽然在其农业利用的演变过程中具有重要意义，可以被认为是美国的农业遗产的一部分，但道路本身更多的被认为是文化遗产，传递着该国对汽车文化的热爱。

此外，美国保护指南显示，洲际80号公路如同其余大多数州际公路系统一样有资格录入美国历史名胜登记册，因其技术上的历史意义以及它与交通发展历史的联系。在2005年3月10日，历史保护咨询委员会确认了州际公路系统的资格，并确认更新的道路，以满足未来的交通需求。并且，委员会通过了“第106条关于对州际公路系统豁免的实施”。这条协议将洲际80号公路和部分其他州际公路系统从第106条国家历史保护行动（NHPA）中脱离，除了沿路线的一些关键功能（主要是桥梁、工艺品和具有特别意义的工程）。[13]

洲际80号公路向我们清晰地展示了道路作为文化景观的“混乱”。尽管它同时作为一种历史景观和一种日常/普通文化景观存在，第106条法案的豁免从本质上确保了州际80号公路和美国其他的州际公路一样，能够不断地改变以适应更多的运输货物量和经济需求。事实上，当前（2016）对州际80号公路的规划研究以及未来的规划方案提出了继续扩大路基的设想，即扩展至6车道以为未来发展提供充足的空间。

然而，为了努力去寻求保护这条道路的办法，2004年爱荷华州立大学的研究人员说服了爱荷华交通部不仅要考虑规划和保护这条路，而且还要考虑更宏观的爱荷华景观，于是于2006年开始了一项“维护爱荷华的形象”的走廊管理计划。它运用景观视觉质量的研究方法，试图确定重要的自然和文化资源。这些资源有助于直观的驾驶体验，反映出国家的文化和历史，代表着自然景观和典型的爱荷华式开发的景观。[14]研究调查了3英里（4.83km）宽道路走廊的两侧：首先记录一些要素，如形式、线性、颜色和具有视觉体验的纹理特征，然后确定经济、土地、文化、生态和具有过去历史及未来发展特征的道路交通资源。该计划还确定了经济增长的区域和指导方针，以及沿着走廊的城市发展，试图保持风景历史资源和经济增长之间的平衡，兼顾爱荷华州的新旧景观，并且允许爱荷华州“未来景观”的发展。也就是说，该项目不仅试图寻求历史文化的价值，还在寻找道路在先今时代的意义。这个项目对于道路保护来说是十分重要的，因为它与传统的保护方法相反。不是把历史看作一组静态的文物或视域，“爱荷华形象”计划将历史纳入一个更广泛的文化定义，旨在保护一个不断发展的文化和变化的景观，而不是一组静态的文物。

6　总结

总之，这些研究案例都表现是近100年或不到100年内的景观需要思考的事情，这个年限涵盖了（长寿的）人类的寿命。这些道路确实是一种快速变化的景观，所以那些“保护”它们的想法可能有点言不由衷。正如洲际80号道路所显示的那样，道路的保护与下一个创新的设计之间相差并不远。这些文化景观使得保护主义者们面临着对于重新设计与保存的反对意见，因为一方面，技术促进了改革，而另一方面，保护主义者们却想冻结景观中的时间。机动车道路使得保护主义者们很难去将历史浪漫化；相反，他们要求设计师、规划师和道路使用者把过去和未来放在同等位置，因为道路在他们的使用过程中可能是普通的景观，然而在设计中却可以是十分精彩的。无论从客观还是隐喻的角度看，道路都穿行在景观中，这使得道路作为文化景观的界定和划分变得更困难。在景观保护当中，最大的两个挑战可能就是背景环境和变革间的冲突，而道路景观需要我们同时关注这两点。

1　Introduction

Following a spate of optimistic, "everyday" cultural landscape studies at the end of the twentieth century, such as J.B. Jackson's "ideological" studies and Grady Clay’s study of roadside "strips," automobile roads have largely disappeared from recent cultural landscape research[1-2]. This may in part be due to the fact that we no longer think about roads-and the cars they support-optimistically, but rather as contributors to global climate change. Roads are "messy" cultural landscapes.They are not based on traditional, time-honored humanland relationships. Instead, they represent a generic, global culture, and in fact often act as disruptors of other cultural landscapes-as conveyors of technology and dividers of habitat.

Roads are also “messy” in that they don’t neatly fit into defined cultural landscape hierarchies. UNESCO defines cultural landscapes in three categories, as seen in Table 1[3]. Roads would appear to belong in the category of intentional, "clearly-defined landscapes." However, they also share characteristics with "organically evolved landscapes," and might be considered "continuing landscapes," defined by social and economic imperatives of technology in response to the natural environment.These imperatives, which include heroic scales of financing and construction, make roads both highly permanent landscapes yet also liable to change. High economic investment and large construction sites mean roads are oftenbut not always-more liable to be adapted than replaced or abandoned. The rapid pace of change in automobile technology and population growth and mobility) leading to increased roadway use are additional drivers of change and evolution. Stated another way, roads might be described as "fast change" landscapes.[4-5]

The other issue that makes roads "messy" landscapes is that they are difficult to define: what is the resource? Is it the road, the right of way, the view from the road, or the landscape the road moves through? In a recent survey of roadway literature, Grazuleviciute-Vileniske and Matijosaitiene address these questions in a complex model, which may be simplified as follows:

A. Road as cultural heritage("historic road")

B. Road landscape as cultural heritage ("significant context")

C. Cultural heritage in road landscape ("historic objects next to road")[6]

The classification system Grazuleviciute-Vileniske and Matijosaitiene propose is perhaps most useful in that it helps determine what road features and elements are highly valued, and hence worthy of protection.If the road is considered as cultural heritage, then engineering structures(bridges, culverts, curbs) are worthy; If the road’s surrounding landscape is considered as cultural heritage, then the landscape element in view from the road (hedgerows, fields, agricultural or other structures in view from the road) are the significant elements to be preserved; and if the road goes past cultural heritage elements, then cultural features next to the road (historic buildings, sites, monuments) are those elements targeted elements for preservation. However, this model has limitations, a key one being the fact that many roads exhibit characteristics of all three of these categories. Although Grazuleviciute-Vileniske and Matijosaitiene concede this, the “mixed road”classification is a small part of their classification framework.

These issues-which are largely concerns about the relationship between a road and its surrounding context-make preserving historic road landscapes challenging. Change in the road may affect context and change in context may affect the road. When moving beyond documentation to active work, it is often only in rare cases where a road may be restored back to its historic conditions; more often preservation requires a transformation or adaptation in the way the road is constructed, used, or perceived. In this article, four case studies at local, regional, and national scales from the United States are used to discuss the ways change and context interrelate in the preservation treatment of road landscapes. The following case studies first classify the four roads and then describe how preservation efforts have resulted in adaptations or transformations of both the roads and of approaches to preservation practice.

2　Case Study 1. Rim Rock Drive

Rim Rock Drive, located in Fruita, Colorado is 22.42 miles long and can be classified as a historic road or a road that is cultural heritage. It is the primary means of experiencing Colorado National Monument [Figure 1].Colorado National Monument is a relatively small (20,500 acres/8,300 ha) park established in 1911 to protect significant geological features of the Pre-Cambrian, Triassic, Jurassic, and Cretaceous periods.Rim Rock Drive began as crude trail built by a park booster John Otto, but during the Depression the National Park Service (NPS), using labor from the Civilian Conservation Corps (CCC), extended and constructed Rim Rock Drive as a motor road. The road exhibits "heroic" engineering, scaling steep slopes; in its construction, large areas of rock were dynamited to create the roadbed and tunnel through cliffs; and large retaining walls were built to pin the road to narrow ledges. Though relatively dry, the climate is characterized by brief but intense rainfalls, so over 200 culverts, approximately 10 per mile, both large and small, were constructed to move water across the roadway. The road is listed on the U.S. National Register of Historic Places and is historically significant for its distinctive construction and engineering and for its association with transportation and recreation during the years 1931-1950.

The road has high integrity to the historic period and has experienced relatively little change, mostly "normal," age-related deterioration and problems due to original construction flaws. These include undersized culverts and swales unable to adequately handle storm water (a problem recognized since 1939).Traditional preservation treatment-based on identification and assessment of the road’s character-defining features-has been quite successful at maintaining the road. This work has included retaining wall repair, roadway resurfacing, and culvert repair and replacement. A major treatment success has been limiting guardrails to only the steepest sections of the road through negotiations made possible following the publication of Flexibility in Highway Design by the U.S. Department of Transportation Federal Highway Administration in the late 1990s. Consequently, there are a number of locations along this road where historic conditions that might be considered less safe have been preserved in order to maintain the road’s original driving experience.

The major pressure on this road that has led to change has been population increase in surrounding areas. In 2014, Colorado was 4th in rate of population growth in the U.S., primarily due to in-migration; the population of nearby Grand Junction has increased 43% since 2000[7]. This has led to increased longer distance tourism and increased local recreation: visitation in the park has been at record levels the past two years, meaning record numbers of visitors have traveled Rim Rock Drive.

Two major transformations have occurred as a result of increased population, neither of which impact the fabric of the historic road per se.First is a contextual transformation, as views and view sheds have significantly changed, to include human settlement and pollution in the background of the geologic futures.Such changes are perhaps more visible at night, when light pollution from high-pressure sodium lighting of parking lots andshopping centers—however beautiful or striking—changes the overall setting of the road, making it more Anthropocene than Pre-Cambrian. Second, are unenvisioned new social uses. Colorado generally, and Grand Junction specifically, is known for its active citizenry and the road now hosts significant new uses of biking and running, both individual and group events, including a major annual marathon. The road is an almost perfect length for this event and boasts an interesting (and challenging, given the road's 2,000 foot elevation change) route for runners. Such uses seem to have less of an impact on the road’s fabric and preservation and more of an issue in terms of park staffing and support. As a public landscape, the park charges minimal or no fees for these uses.

3　Case Study 2. Colonial Parkway

Colonial Parkway is 23 miles long and can be classified as both a historic road and as a road that has cultural heritage in its landscape. It is located in Virginia, and was designed and constructed beginning in 1933 by the National Park Service as part of Colonial National Historical Park. Using the Bronx River Parkway and the Mount Vernon Memorial Parkways as precedents the road was constructed as a state of the art "modern" parkway. However, it did not link parks, but rather three historic sites/landscapes: Jamestown (site of first English settlement in the United States in 1607); Williamsburg (Virginia’s colonial capitol) and Yorktown (site of Cornwallis’s surrender marking the end of the American Revolutionary War). At the time of its construction, Colonial Parkway was technologically innovative with an exposed aggregate surface and a three-lane design. The three-lane design, without road striping, can be considered a "vestigial" design model, since it was later abandoned as road technology improved and a central median became standard. Other advanced or innovative features for the time included the road's stream-lined, modern concrete bridges that carried the road over tidal estuaries. These modern bridges contrasted with the more picturesque, overpass bridges which were constructed of handmade Colonial-style brick, and were seen in the perspectival view down the road. Colonial Parkway was completed in two phases, from 1933 to 1941 and from 1946 to 1958, before and after World War II.Notably, Stanley Abbott-who had "cut his teeth" working on the Westchester County Parkways for Gilmore Clarke prior to designing the Blue Ridge Parkway for the National Park Service in the 1930s-managed the second, postwar phase of the parkway’s construction. The road is historically significant for its distinctive construction and landscape architecture as well as for its associations with transportation and the historic preservation movement[8].

Today, one of the major preservation issues for this primarily local road is population growth in the surrounding region. The road once passed through woodlands; now it passes through housing developments [Figure 2]. Such growth in the road’s landscape context has had two impacts: the first is use of portions of the road for commuting, particularly around the growing city of Williamsburg. The second is increased storm water run-off due to increased impervious paving as a result of development. The road's drainage system, mostly comprised of brick culverts sized 18 to 24 inches (45 to 60 cm) in diameter, was originally designed to handle rural stream flows. Today it cannot handle increased volumes, causing roadway flooding, significant stream bank erosion, and woodland degradation. The National Park Service has used a traditional preservation approach of "rehabilitation"-upgrading culverts as infrastructure-to address this problem. This has included replacing historic culverts and drainage structures with new, larger culverts-in some cases more than twice the original size, particularly in key in key flood locations[9].These culverts, though much larger and constructed of concrete are clad in brick. Their design has followed U.S. preservation guidelines as contained in the Secretary of Interior's Standards for the Treatment of Historic Properties, in that they are compatible with the existing resource yet are clearly distinguishable as new construction (Secretary of the Interior)[10].It is worth noting that this rehabilitation of the road’s drainage infrastructure is also mitigated by the fact that it is largely invisible, as culvert changes run parallel to the road and are out of the motorist's view shed.

This case study shows how perception of a road can be transformed over time and how its use can be transformed through preservation treatment. Seen as a technological advance at the time of its construction, today Colonial Parkway is viewed as a historic roadway, though parts of it, completed after World War II, are only barely 50 years old. Similarly, once a tourist and recreation route, portions of it are now seen as a commuting route. This is in contrast to Rim Rock Drive, where recreational uses have increased. Happily, traditional preservation techniques have facilitated changing uses while at the same time mitigatingcharacter change.

4　Case Study 3. Lincoln Highway in Iowa

As one of the first trans-continental highways in the United States, traversing 3,400 miles (5,470 km) across the United States, the Lincoln Highway can be considered to be a historic road or a road that is cultural heritage of the United States. It was conceptualized in 1913 by a group of automobile industrialists headed by Carl G. Fisher, who organized the Lincoln Highway Association (LHA). The road was not federally funded, but instead financed by local chapters of the LHA and local (state and county) governments, who in some cases utilized existing roads and in others built new alignments.The process often included the construction of "seedling miles" where road proponents built short, 1-mile segments using the most up-to-date road construction. Local governments could then implement or aspire to the preferred road standards, which included concrete paving, guardrails and plantings.Perhaps the most famous seedling mile was located in Illinois and was designed by noted landscape architect Jens Jensen. The Lincoln Highway is significant in that it fostered an automobile culture, systemized and standardized road construction, and eventually helped lead to the 1956 Federal Highway Act and the U.S. Interstate System.

In Iowa, approximately 300 miles (480 km) of Lincoln Highway was constructed, some along existing gravel routes and some along new alignments. The road was also rerouted numerous times as the Iowa Chapter of the LHA sought to determine the "best route" across the state. Eventually, the road was renumbered as U.S. Highway 30.Although it became a well-known national route, after 1960, the Lincoln Highway in Iowa was overshadowed by Interstate Highway 80, which duplicated the Lincoln Highway route 40 miles to the south. The Lincoln Highway subsequently became a regional route, primarily serving state audiences. Today it is historically significant for its association with transportation and the development of automobile culture in the United States for the years 1913 to 1956.

Today, individual states have varying approaches to the preservation of the Lincoln Highway. In Iowa, state and county governments are active in the road’s preservation as is the Iowa Chapter of Lincoln Highway Association, which was re-established in 1992 to "preserve and restore the memory of the highway to celebrate its meaning and national significance." In 2004, the Iowa Department of Transportation (IDOT) employed Iowa State University to map, analyze and create a corridor management plan for the historic roadway, addressing 3 main issues:the road’s historic design and features; its roadside architecture, and adjacent development dating to 1913-28. Comparing existing conditions and historic photos, they correlated IDOT engineering elements with the Secretary of Interior’s aspects of integrity[11]. This led to the identification of primary elements-key to maintaining integrity and character, and secondary elements, which could potentially be lost and still maintain integrity. Primary features included: alignment, association with the railroad, roadside vegetation, pavement material, width of the right-of-way, ditch and shoulder material, associated utilities, and adjacent landscapes with high integrity of historic land use (e.g., agricultural use) [Figure 3]. Secondary features included pavement width, structures, appurtenances, ditch slopes, and adjacent landscapes with low integrity of historic adjacent land use. Mapping and planning required extensive stakeholder input and included consultations with county engineers, the Iowa Lincoln Highway Association; the Highway 30 Coalition (a local economic development group promoting development of a 4-lane highway); and focus groups of Iowa citizens (including farmers, commuters, recreational users).

Keller and Butler's Corridor Management Plan led to the designation of the Lincoln Highway as a Heritage Scenic Byway. Scenic Byways in the U.S. were a part of a national program of the Federal Highway Association (FHWA), which provided funding for road protection in the 1990s.After 2012, the program was shifted to the states, and since 2006, the Lincoln Highway Byway in Iowa has been managed by a non-profit organization in conjunction with the Iowa Department of Transportation and local county engineers.

Under the scenic byway model, preservation of the Lincoln Highway has been strongly focused on community/economic development through cultural heritage tourism. Although key engineering features (such as bridges and gravel segments) are preserved, the road has been transformed into a marketing tool to support local businesses and draw tourism to places bypassed by the interstate highway that runs to the south.Studies in other states show byway designations increase tourism and tourism revenues, though exact economic benefits can be hard to quantify[12]. In many ways, the Lincoln Highway today is as much an imageor a brand as it is a place. Where historic elements are missing, the image of the roadway is kept alive via Lincoln Highway signage. In other places, social events, such as a 300-mile long rummage sale and an annual vintage car tour, keep the memory of Lincoln Highway alive. The image is further supported by numerous sanctioned and independent Lincoln Highway websites. Viewed on a smart phone, these sites obviate the need for physical interpretation and reach new audiences. Although the recasting of the Lincoln Highway as a "scenic byway" has not necessarily led to improved preservation of the physical road, it has significantly changed the way the road is valued and interpreted by the communities it passes through.

5　Case Study 4. Interstate 80 in Iowa

Interstate 80 (I-80) replaced the Lincoln Highway as Iowa's most important east-west/ trans-continental transportation road. The road, running 306 miles (492 km) through the state, was part of the Federal-Aid Highway Act of 1956 (also known as the National Interstate and Defense Highways Act), which provided $25 billion to build 41,000 miles of highway across the United States. Interstate-80 was designed to 1950s FHWA standards as a four-lane road with diamond and cloverleaf interchanges, efficient routing, long, spiral curves and services placed outside the right of way. The road was built over 14 years, with its first sections completed in 1958, and its last sections in 1966.By the early 1980s, traffic volumes had reached design capacity and the road was reconstructed along its full length from 1985-1988 [Figure 4].

I-80 is a significant cross-country route and carries large volumes of trucks and automobiles. In Iowa, it passes through one of the United States’ key farming regions, the "corn belt," a vast landscape of corn and soybean fields, dotted with historic and contemporary agricultural structures. This landscape, though continuing in its evolution in terms of agricultural use, can be considered part of the United States’ agricultural heritage, as much as the road itself can be considered cultural heritage, expressing the country's love of the automobile.

In addition, at more than 50 years old, I-80, like the much of the rest of the Interstate System, is, according to U.S. preservation guidelines, technically "historic" and eligible for the U.S. National Register of Historic Places for its association with transportation history. Recognizing both the eligibility of the interstate system and acknowledging the desire to update the roads to meet future transportation demands, on March 10, 2005, the Advisory Council for Historic Preservation adopted the "Section 106 Exemption Regarding Effects to the Interstate Highway System." This agreement exempts I-80 and the rest of the Interstate System from Section 106 of the National Historic Preservation Act (NHPA), with the exception of key features along the route (mostly bridges, artwork, and significant engineering)[13].

I-80 shows clearly the "messiness" of roads as cultural landscapes. Although it simultaneously exists as both a "historic landscape" and an "everyday/ordinary cultural landscape," the "Section 106 Exemption" essentially ensures that I-80, like other interstates in the United States, will continue to change and transform to meet economic and functional imperatives of transporting more people and goods. Indeed, the current (2016) planning study and guidelines for the future of I-80 plan proposes to continue to expand the roadway, to include 6 lanes of traffic plus room for future expansion.

However, in an effort to look at the preservation of this roadway differently, in 2004researchers at Iowa State University convinced the Iowa Department of Transportation (IDOT) to consider planning and preserving not just the road, but also the larger Iowa landscape it moves through in a 2006 Corridor Management Plan entitled "Maintaining the Image of Iowa." Applying methods from landscape visual quality studies, this project sought to identify the significant natural and cultural resources that "contribute visually to the driving experience, reflect the culture and history of the state, and represent the natural and developed landscapes that typify Iowa."[14]It surveyed a 3-mile wide corridor on both sides of the road: first documenting the elements of form, line, color and texture features that characterized the visual experience and then identifying economic, agrarian, cultural, ecological and transportation resources that characterized the past history and future development of the road. The plan also identified areas and guidelines for economic growth and urban development along the corridor, seeking to balance preservation of scenic and historic resources with growth and development, embracing the "old landscape"of Iowa and the "new landscape" of Iowa, and accepting the development of a "future landscape" of Iowa. Stated another way, the project sought to identify the cultural significance not just ofthe past, but also of the present. This project is significant for roadway preservation because it sits in contrast to the idea of traditional preservation approaches. Instead of seeing history as contained in a set of static artifacts or view sheds, the "Image of Iowa" plan in corporate history into a broader definition of culture and seeks to preserve an evolving culture and a changing landscape rather than a set of static artifacts.

6　Conclusion

In conclusion, it is worth considering that these case studies address landscapes at or just under 100 years old, encompassing the life span of a (long-lived) human. These roads are indeed "fastchange" landscapes, and the idea of "preserving" them may actually be somewhat disingenuous. As I-80 in particular shows, the preservation of a road is actually never very far away from the next innovation in design. These cultural landscapes require preservationists to confront opposing ideals in design and preservation, as on the one side technology promotes change while on the other preservationists seek to freeze landscapes in time. Automobile roads make it difficult for preservationists to romanticize the past; instead, they require designers, planners, and road users to juxtapose the past and the future, because roads are both ordinary landscapes in their usage yet can be extraordinary in their design. And roads make it difficult to isolate and draw boundaries around cultural landscapes because they run through landscapes, both metaphorically and physically. Context and change are probably the two greatest challenges in landscape preservation, and road landscapes make us look at both.

（References）：

[1]Jackson, J.B. “Roads Belong in the Landscape”in A Sense of Place, A Sense of Time New Haven: Yale University Press. 1994.

[2]Clay, Grady. “Strips” in Close-Up: How to Read the American City. New York: Prager, 85-109.1973.

[3]Mitchell, N., M. Rossler, and P. M.Tricaud, (eds). World Heritage Cultural Landscapes: A Handbook for Conservation and Management. World Heritage Papers 26, Paris: UNESCO. 2009.

[4]Selman, Paul. Sustainable Landscape Planning: The Reconnection Agenda. New York: Routledge. 2012.

[5]Roe, Maggie. "Exploring Future Cultural Landscapes"in Maggie Roe and Ken Taylor (eds), New Cultural Landscapes. New York: Routledge, 241-269. 2014.

[6]Grazuleviciute-Vileniske, Indre and Irina Matijosaitiene. "Cultural Heritage

of Roads and Road Landscapes: Classification and Insights on Valuation." Landscape Research, 35:4, 391-413. 2010.

[7]Svaldi, Aldo. "Colorado Ranks Fourth Among States for Population Gains." Denver Post, 23 December 2014.http:// www.denverpost.com/2014/12/23/colorado-ranks-fourthamong-states-for-population-gains/

[8]Heritage Landscapes (Patricia O'Donnell, Principal). "Cultural Landscape Report for Colonial Parkway, Part 1: Site History and Existing Conditions." National Park Service. 1997.

[9]National Park Service, Colonial National Historical Park. "Environmental Assessment/Assessment of Effect: Redesign Parkway Drainage along Papermill Creek Watershed." 2006. https://parkplanning.nps.gov/document. cfm?parkID=218&projectID=13388&documentID=13911.

[10]Secretary of the Interior. Standards for the Treatment of Historic Properties. National Park Service. 1995. https:// www.nps.gov/tps/standards/four-treatments.htm

[11]Keller, T., P. Butler, and C. J. Seeger. "The Tale of Two Corridors: The Lincoln Highway and Interstate 80: Issues in managing Historic and Contemporary Routes." Presented at Preserving the Historic Road in America Conference. National Trust for Historic Preservation. Portland, Oregon. 2005.

[12]Petraglia, Lisa and Glen Weisbrod. "Review of Impact Studies Relative to Scenic Byway Designation." National Scenic Byways Resource Center. 2001.

[13]"Exemption Regarding Historic Preservation Review Process for Effects to the Interstate Highway System." Federal Register Vol 70: 46 (10 March 2005), 11928-31. http://www.achp.gov/docs/final_interstate_exemption_ notice.pdf

[14]Seeger, Christopher J. "Maintaining the Image of Iowa: Mapping the Natural, Cultural, Agrarian, and Scenic Features Adjacent to Iowa's Interstate 80." Presented at the Transportation Research Board Annual Meeting. 2004.

Considering Change and Context in the Preservation of Road Landscapes

The literature of cultural landscapes contains abundant road studies by Jackson, Clay, and others. However, the actual preservation of transportation corridors poses numerous challenges, most of which stem from their long and narrow character: although preservation of a road’s structures (roadbed, curbs and culverts) may be straightforward due to their relative simplicity and the road’s jurisdiction under a single agency, preservation of the corridor context is usually more difficult, due to its vast expanse, myriad stakeholders, and rapid change. Situated in larger social and environmental networks of communication and transportation and affected by rapid technology change, roads are “fast change” landscapes, their use, experience and character evolving over time. Given such changes how can preservation be accomplished—or justified—over the long distances of transportation corridors?Four case studies from the United States explicate preservation challenges at local, regional and national scales.Discussion of parkways, scenic byways, and highways describes preservation approaches that permit ongoing transformation and evolution of these resources.

Road; Landscape; Context; Parkway; Byway

TU986

A

1673-1530（2016）08-0058-11

10.14085/j.fjyl.2016.08.0058.11

2016-07-06

2016-08-03

海蒂·霍曼，美国风景园林师协会会员，注册风景园林设计师，为美国爱荷华州立大学风景园林副教授。

Author:

Heidi Hohmann, ASLA, RLA, is an Associate Professor of Landscape Architecture at Iowa State University, Ames, IA, USA.

何明一/1991年生/男/硕士/北京林业大学园林学院（100083北京）

王亮/1993年生/男/硕士/北京林业大学园林学院（100083北京）